(a) The board shall, as provided by this act and by the provisions of existing law, examine and revise the assessments and valuations, increasing or decreasing the same as in their judgment may seem proper, and shall add thereto such property or subjects of taxation as may have been omitted.

(b) After such revision, the board shall, by rule, fix convenient times for the hearing of appeals from said assessments and valuations.

(c) In any appeal of an assessment the board shall make the following determinations:

(d) The board, after determining the current market value of the property for the tax year in question, shall then apply the established predetermined ratio to such value unless the common level ratio varies by more than fifteen percent (15%) from the established predetermined ratio, in which case the board shall apply the common level ratio to the current market value of the property for the tax year in question. For the initial year of the implementation of county-wide reassessment, appeals shall be solely on the basis of fair market value.

(e) Nothing herein shall prevent any appellant from appealing any base year valuation without reference to ratio.

(f) Except as provided for in subsection (g), the valuations determined in accordance with this section shall stand as the valuations for the assessments of all county and institution district taxes and for such other political subdivisions as levy their taxes on county assessments and valuations in the county until the next triennial assessment.

(g) Persons who have suffered catastrophic losses to their property shall have the right to appeal before the board, within the remainder of the county fiscal year in which the catastrophic loss occurred, or within six (6) months of the date on which the catastrophic loss occurred, whichever time period is longer. The duty of the board shall be to reassess the value of the property in the following manner: the value of the property before the catastrophic loss based on the percentage of the taxable year for which the property stood at its former value, added to the value of the property after the catastrophic loss, based on the percentage of the taxable year for which the property stood at its reduced value. Any property improvements made subsequent to the catastrophic loss in the same tax year shall not be included in the reassessment as herein described for that tax year. Any adjustment in an assessment pursuant to this subsection (1) shall be reflected by the appropriate taxing authorities in the form of a credit for the next succeeding tax year; or (2) upon application by the property owner to the appropriate taxing authorities, shall result in a refund being paid to the property owner at the time of issuance of the tax notice for the next succeeding tax year by the respective taxing authorities. For purposes of this subsection, the phrase “catastrophic loss” shall mean any loss due to mine subsidence, fire, flood or other natural disaster which affects the physical state of the real property and which exceeds fifty percent (50%) of the market value of the real property prior to the loss.